Autoboxing and Unboxing

• automatic conversion : Primitive types ↔︎ Wrapper classes
  • int ↔︎ Integer
  • long ↔︎ Long
  • double ↔︎ Double
  • boolean ↔︎ Boolean
  • char ↔︎ Character
  • byte ↔︎ Byte
  • short ↔︎ Short
• Autoboxing is for primitive types to Wrapper classes
• Unboxing is for opposite direction
• ex) int ↔︎ Integer, float ↔︎ Float, long ↔︎ Long

javaCopy
List<Integer> li = new ArrayList<>();
for (int i = 1; i < 50; i += 2)
    li.add(i);

javaCopy
Character ch = new Character('a');
Integer i = new Integer(3);

ref

• https://docs.oracle.com/javase/tutorial/java/data/autoboxing.html